We know that survival rates are bad for premature babies born in the 22nd week because many of them are too tiny and too underdeveloped to live outside the womb. But, there’s a great variation in how these preemies are treated. Which is the bigger influencer in survivability, or the hospital’s practices on whether to initiate care?
An article published last week in the New England Journal of Medicine explores this question. It’s a particularly relevant question for our family as our son was born at 22 weeks and 6 days of gestation. During our pre-birth counseling, the on-duty neonatologist said, “At this stage, I don’t recommend that babies should be intubated just because the results are so poor. If you give birth after midnight — that’s just the line for when we’ll intervene — I’ll be the one who comes and resuscitates the baby, but my heart won’t be fully in it.”
Gabriel was born 40 minutes before midnight, and the neonatologist did make an exception, and treated Gabriel and did a good job, but we nicknamed him “Dr. Grumpypants” for his uncooperative attitude.
This study was of 4,987 births in 24 hospitals that participate in the Neonatal Research Network. Here are some things that this study found:
- 22 percent of 22 weekers got treatment, and 23 percent of the treated survived.
- 72 percent of 23 weekers got treatment, and 33 percent of the treated survived.
- 97 percent of 24 weekers got treatment, and 57 percent of the treated survived.
- All infants not getting treatment in these groups died.
- Doctors tended to “round up” a bit with the gestational days. That is, there’s a big jump in the willingness to treat at the end of the 22nd week. At 22/4, around 10 percent of babies got treated, at 22/5, about 30 percent of babies got treatment, and at 22/6, 50 percent of babies were treated. Same thing happens at the end of the 23rd week. At 23/4, about 70 percent of babies are treated, but then on 23/5 and 23/6, it jumps to 85 percent.
Then the study looked at a more complicated question, why survival rates vary greatly between hospitals. Another way of stating this question is that doctors sometimes say they won’t provide care before 22 weeks because the babies won’t survive anyway. Is that true?
The answer they came to was that rates of providing treatment accounted for 78 percent of between-hospital variation in survival of 22-week preemies. I think what this means is that they looked at a whole bunch of factors that could affect the survival of a preemie — whether the mother had received prenatal care, whether she had received steroids before birth, whether the baby was a singleton or a multiple, and several others. Then they did a thing called multi-level logistic-regression, a statistical analysis method I studied once in a stats class 10 years ago. What regression allows you to do is to separate each factor from the others and say how influential it is in determining the outcome, and they found that 22-week preemies are more likely to survive if born at a hospital that has a higher rate of active treatment. (I sort-of get this — I need to run it past some more statistically inclined relatives to really understand it.)
Another way of stating this result is to say no, it isn’t futile to treat 22-weekers, and a hospital that is willing to treat them makes a huge difference to them.
This information is a big deal regarding two important parts of the birth of a micropreemie. One is the willingness of a doctor and hospital to provide treatment in the 22nd week. At first, our doctors weren’t willing to provide it, even though we wanted it. The second part is how this information is presented to parents about to have a preemie at the edge of viability. Often, parents are told that 22 weekers can’t survive, or that a tiny percentage, for example, 5 percent of them, survive. That 5 percent number combines treated and untreated babies in to one group, and is technically true, but inappropriate for the situation. In the 23rd week, parents asking for non-treatment generally have that wish respected.
The article was accompanied by an editorial from a British doctor, Neil Marlow, who wrote, “To give crude data on the survival rate among all such infants, regardless of whether treatment efforts were made, is misleading and helps to make poor survival a self-fulfilling prophecy.” He concluded: “Information on survival, morbidity, and policies regarding active intervention should be available to assist parents in making an informed choice about transfer to a specialist hospital, if feasible, and the level of intervention provided after birth.”
If you want to read other articles written about this study, here’s an article published in The New York Times last week.